Technique Treats Central Venous Occlusion in Dialysis Patients
Marcelo Guimaraes, MD
SAN FRANCISCO—A radiofrequency (RF) wire technique appears to be a safe alternative for managing benign chronic central venous occlusions when conventional techniques have failed, according to findings presented at the 37th Annual Scientific Meeting of the Society of Interventional Radiology.
“We have been the pioneers on this,” stated study investigator Marcelo Guimaraes, MD, Associate Professor of Vascular and Interventional Radiology at the Medical University of South Carolina in Charleston. “We have been doing this now for four years and probably this is the largest experience in the world with this procedure. We only treat symptomatic patients or patients who are on dialysis and the AV [arteriovenous] graft or fistula is showing malfunction.”
Dr. Guimaraes and his colleagues analyzed the outcomes of 31 patients (15 female) ranging in age from 35-78 years who were treated between June 2008 and January 2011. In these patients, previous attempts at recanalization using mechanical catheter/wire techniques had failed. The patients presented with a swollen arm and/or face secondary to benign central venous occlusions (7 subclavian veins, 19 brachiocephalic veins, and 5 superior vena cava veins) related to tunneled catheters. Simultaneous upper extremity (brachial approach) and central venograms (femoral approach) defined the central occlusion site.
The investigators used the PowerWireTM RF (Baylis Medical, Canada) wire, which was advanced within a 5-Fr KMP catheter. With this approach, a pre-stent 4 mm balloon angioplasty was followed by 9-12 mm stent placement. If the RF wire puncture was inadequate, the clinician pursued a new location. Clinical and venogram follow-ups occurred at 30 days post-treatment and again at 3, 6, and 12 months.
The RF wire technique successfully treated 29 patients. The procedure was aborted in one patient the problem was due to hemothorax that occurred before the use of RF wire, which was successfully treated with a chest tube without clinical repercussions. All of the successfully treated patients had resolution of symptoms after a mean follow-up of 6 months. Two of the 29 patients experienced stent occlusion within 30 days; the remaining stents were patent at nine months. The patients were asymptomatic in all 27 cases.
“We are now getting nephrologists referring patients from other parts of the country,” Dr. Guimaraes told Renal & Urology News. “The complications have been very rare and the results of this technique are impressive. Because we use RF wire recanalization only after failure of conventional endovascular techniques, the patients would have either left untreated or the alternative would be an open chest vascular by-pass surgery that typically has high morbidity and inadequate long term patency rate.”
The real key to the success with this technique is very close follow-up, Dr. Guimaraes said. “This is like when you buy a car,” he said. “We know there will be need for maintenance of the stent but, at this point, we don't know if it will be in three months or in three years.”
Thus, he explained to the patients that they need to return to the Vascular & Interventional Radiology Clinic for an evaluation as soon as they experience symptoms, he said.